REPORT OF NATIONAL MUSEUM, 1918. 65 



voted to systematic geology, paleobotany, and the east end of the 

 hall set apart for vertebrate paleontology, were completely dis- 

 mantled and closed to the public. The present crowded condition 

 of the remaining halls by the temporary storage of specimens and 

 cases, has necessarily reduced both the value and attractiveness of 

 the exhibits. It is hoped that conditions will so improve during the 

 next fiscal year that the halls can be restored to their former state. 



Explorations. — During the field season of 1917 an expedition 

 under Secretary Walcott's direction spent fifty days at the Burgess 

 Pass Camp, 3,000 feet above Field, British Columbia, where a sec- 

 tion of about 180 square feet was taken out, practically exhausting a 

 quarry which has given the finest and largest series of Middle Cam- 

 brian fossils yet discovered, and the finest invertebrate fossils ever 

 found in any formation. More than a ton and a half of material 

 was shipped to Washington for the National Museum collections. 



This expedition also visited Lake McArthur to verify a geologic 

 section, and then made the Vermilion River trip, making new ex- 

 plorations particularly in the vicinity of Mount Breese and Breese 

 Pass. 



Dr. Merrill was detailed in February to locate quartz suitable for 

 supersonic work by the Council of National Defense — a work which 

 he continued when detailed in May to make collections for the Mu- 

 seum in Georgia and North Carolina. Numerous specimens were se- 

 cured, some of which have been utilized and others shipped for test- 

 ing as to their suitability for the purpose. Dr. Merrill has since been 

 requested by the Council of National Defense to take general charge 

 of this important work. For the Museum, he secured materials in- 

 cluding albite, columbite, pitchblende, black mica, staurolite, bauxite, 

 quartz, etc., which will fill places in reserve, exhibition, and duplicate 

 series. 



Dr. James C. Martin, assistant curator, was detailed in May to 

 collect material to illustrate the unaltered and the partly or wholly 

 decomposed phases of the more familiar varieties of rocks, for school 

 sets of a rock weathering series. The types selected were granite- 

 gneiss, diabase, soapstone, gabbro, sandstone, and limestone, material 

 for about 2,000 specimens being secured from points in Virginia and 

 Maryland. A second detail in the latter part of June resulted in the 

 acquisition of material for exhibition, reserve, and duplicate series, 

 including feldspar, garnet, emery, nephelite syenite, minette, and 

 suites of specimens showing post-glacial decomposition of crystalline 

 rock. These were obtained from localities in Pennsylvania, New 

 York, and New Jersey. 



In the latter part of July, 1917, Dr. E. T. Wherry, then assistant 

 curator of mineralogy and petrology, visited the well-known mineral 

 locality at Amelia, Virginia, and secured some interesting material. 



91933°— nat mus 1918 5 



